Directions: |
Directions:Preheat oven to 350º. Line muffin pans with paper liners.In a medium bowl, whisk together the flour, baking powder, baking soda and salt. In the bowl of a mixer, cream together the butter and sugar on medium speed until light and fluffy (about 3 minutes). Mix in the peanut butter, beating until well incorporated. Add the eggs, one at a time, beating well after each addition. Mix in the sour cream and vanilla. With the mixer on low, alternately add the dry ingredients in three additions and the buttermilk in two, beating just until incorporated.
Divide the batter evenly among each of the prepared muffin cups, filling each 2/3 full. Bake cupcakes for about 20 minutes or until they spring back when lightly pressed with your finger and a toothpick inserted in the center comes out clean. Let cupcakes cool slightly then remove them to a rack to cool completely.
To make the frosting: In the bowl of the mixer, beat the butter on medium high speed until smooth (about 1-2 minutes). Gradually add the confectioners sugar and beat until incorporated. The mixture will become crumbly at first, but keep beating. It will come together! Add the marshmallow creme and vanilla and beat until light and fluffy (about 2-3 minutes). Transfer the frosting to a piping bag fitted with a decorative tip and pipe the frosting into a swirl on each cupcake. |